by Dan Vergano, USATODAY

by Dan Vergano, USATODAY

Everyone loves the Internet. How else would we learn about dancing mortgage offers, the latest wardrobe slips and the deep insights provided by pictures of cats?

Yes, this modern wonder is surely something any advanced civilization would undoubtedly cherish, just like say, aliens would. And aliens, if they are out there, likely already have one, suggests one space scientist.

"A galactic Internet might be in use already, but by aliens, not by humans yet," says Italy's Claudio Maccone, writing in the current Acta Astronautica journal. Maccone is a co-chairman of the Search for Extraterrestrial Intelligence (SETI) permanent committee of the International Academy of Astronautics. In his wide-ranging report - which ponders everything from the last 3.5 billion years of life to the next 10 million years of humanity undertaking galactic colonization - the notion of aliens with e-mail is among the more mild of his suggestions.

Maccone thinks that space physics explains why aliens, if they are out there, are likely too busy with their own galactic version of Facebook to pay much attention to all the noise coming from Earthly broadcasts of old baseball games and M.A.S.H. episodes, now making their way across space. They likely have a better way to talk to each other, thanks to an effect called gravitational lensing.

Gravitational lensing is an effect seen in astronomy where the tendency of gravity to bend light passing close to anything massive, say a star, can be used to strengthen signals coming from much farther away. Just like astronomical images now captured by the Hubble space telescope, radio messages sent from a spacecraft parked at just the right distance from the star would benefit from the focusing power of gravitational lensing to send radio signals from star to star.

For example, writes Maccone, "suppose for a moment that a human spacecraft was already able to reach the nearest star system," which is Alpha Centauri, about 4.4 light years or 25.7 trillion miles away. "The question would then be: 'What shall we do with that spacecraft after it got there?'" he asks.

The answer is that we would park the spacecraft 51 billion miles farther away on the far side of the star and park another one similarly far away from our own sun, but in the opposite direction. This location is the focal point of the gravitational lens for radio messages between our sun and Alpha Centauri.

"That would enable cheap (in terms of the required powers) radio communications between the two stellar systems," Maccone writes. Boosted by the gravity field of the two stars, radio signals become "quite affordable" from a power-transmission standpoint, although they would still travel at the speed of light. So it would take four years for ads for cheap mortgages on Alpha Centauri illustrated by dancing alien icons to reach us. Still it beats never.

The idea sounds a little crazy, but it also recalls science fiction writer Arthur C. Clarke's 1945 envisioning of geostationary communication satellites ringing the Earth, parked permanently in place at the then-unreachable altitude of 22,000 miles high. Today there are more than 400 circling the globe.

"By this we mean that one or more alien civilizations harboring in the galaxy might have understood the use of radio bridges among stars long ago already. Thus, they might have created a Galactic Internet among the colonized stellar systems according to their needs," Maccone writes. "This is no science fiction: It is just the physics of star gravitational lensing applied to more than one civilization in the galaxy."

Hey, what about us? Well, for now the focal point between our sun and the nearest star is more than four times the distance that NASA's Voyager 1, the most distant spacecraft ever launched, has traveled away from the sun.

Maccone argues we may not want those advanced aliens to notice us just yet, anyway. Basically, he calculates there is an "appalling" evolutionary gap between humanity and an alien species that has already colonized space. We would just be bugs to them, in terms of evolution.

Which might explain why they aren't talking to us now. An alien talking to a less-evolved human might look like one of your neighbors trying to chat up a petunia.

Along those lines, a 2007 National Research Council report said, "It is certain that nothing would alter our view of humanity and our position in the cosmos more than the discovery of alien life." The discovery of more than 800 planets circling nearby stars since 1995, and the hints that many stars in our galaxy likely host planets in "habitable zone" orbits amenable to life has certainly started many people besides Maccone thinking about meeting those aliens.

MIT planet hunter Sara Seager recently updated estimates of the likelihood of NASA's 2018 James Webb Space Telescope detecting the signature of alien biology on a nearby star's planet elsewhere. Two worlds will likely turn up in its field of view with biological signals of life on them, she estimates.

Whether such aliens will want to see our cat pictures is another question. SETI efforts have begun to turn away from searching for messages sent directly to Earth by more highly evolved aliens - turning instead to a "long stare" radio program devoted to catching faint signs of their radio traffic to each other.

That makes much harder the task of deciding whether "provocative" signals overheard by SETI are real, rather than just random noise or false alarms, says statistics professor Thomas Hair of Florida Gulf Coast University in another new Acta Astronautica journal study

Imagine aliens trying to make sense of "Yabba Dabba Doo" or "Where's the Beef?" or any of the other stuff we have been broadcasting for a century. When it comes to eavesdropping on aliens, Hair writes, "The finest mathematical sieve will always gather up far more straw from the haystack than it does those very special needles."

Still, it is likely worth the effort, Maccone suggests. On Friday, the United Kingdom announced a new SETI network there of 11 observatories and schools trying to hunt for alien radio signals.

Even though the weak radio signals from a galactic Internet would be very difficult to overhear, pursuing efforts to listen for aliens such as SETI makes sense, Maccone argues, unless we want to go the way of the Aztecs. Meeting the only slightly-more-advanced (and disease-carrying) Conquistadors without warning didn't go so great for them the last time that a "New World" was discovered. And hey, there is always the chance that those aliens will have some really great cat pictures.